Possible Cause:
Oil-based paint or vinyl acrylic latex paint was applied to new masonry that has not cured for a full year.
Fresh masonry is likely to contain lime, which is very alkaline. Until the lime has a chance to react with carbon dioxide from the air, the alkalinity of the masonry remains so high that it can attack the integrity of the paint film.

Solution:
Allow masonry surfaces to cure for at least 30 days, and ideally for a full year, before painting.
If this is not possible, apply a high quality latex severe weather primer followed by a premium latex house paint. The acrylic binders in these paints resist alkali attack.